Gate-valve.



A. WATSON.

GATE VALVE. APPLICATION FILED SBPT.2'7,1911.

Zgfivaaaea- Patented Feb. 6, 1912.

UNITED STATES PATENT OFFICE;

ALEXANDER WATSON, 0F BEACI-IMON'I, MASSACHUSETTS, ASSIGNOR TO BYRON C.LEAVITT, TRUSTEE, OF DUXBURY, MASSACHUSETTS.

GATE-VALVE.

Specification of Letters Patent.

Patented Feb. 6, 1912.

To all whomz't may concern Be it known that I, ALEXANDER VVATSON, acitizen of the United States, and resident of Beachmont, in the countyof Suffolk and State of Massachusetts, have invented new and usefulImprovements in Gate-Valves, of which the following is a specification.

My invention relates to the construction of gate valves and has for itsobject the production of a simplified and reliable gate valve requiringa minimum of machine work and affording all the advantages incident to aclear straight passage for fluids when the valve is open;

In the drawings hereto annexed which illustrate my inventionFigure 1 isa vertical section of a valve showing some of the parts in elevation andothers in dotted lines; Fig. 2 is a top plan view of the valve casingwith the hood thereof removed; Fig. 3 is a top plan view of the valveand its carrier; and Fig. 4 is aside view of the valve and its carrierand a portion of the operating means.

The valve casing comprises a main oham= ber C, an inlet branch I andoutlet branch 0., these two branches being preferably in the same axialline. The main chamber G extends at right angles to the inlet I andoutlet 0 to a distance sufiicient to provide a housing for the valvewhen the latter is fully open. A portion of the wall of the main chamberis made thicker than the remainder so that this portion indicated by Chas an internal surface slightly smaller in radius than the generalinternal surface of the main chamber C. The surface of this portion Cconstitutes the valve seat and extends for a substantial distance oneither side of the inlet opening. A guiding groove at each side of theinterior ofthis main chamber 0 is provided by the ribs R, R. the tops ofwhich are approximately flush with the cylindrical surface which wouldbe formed by a continuation of the cont-our of the valve seating surfaceat C. The inlet and outlet openings I and O are internally threaded asusual. The upper end of the main chamber C is externally threaded andthe internal machining of the valve casing is accomplished by theintroduction of a reamer which perfects the cylindrical surface of thesaid portion C and at the same time reams a flat seat at that end of thechamber G which may be called the bottom.

at C It will be observed by reference to Fig. 2, that the introductionof such a reamer will leave the ribs R, R, untouched or at all events,will not remove enough material from them to affect their utility whichis presently to be described.

A cap or hood H screws onto the top of the chamber C and receives at itsthreaded upper end a threaded extension of the sleeve N which has also asimilar threaded extension which takes the gland nut G.

A stem S provided wit-h a collar S and having its lower portion threadedat S passes through the passage provided by the nut G, sleeve N, and capH. The collar S which is preferably integral with the stem S is confinedbetween an internal shoulder h and the threaded projection of the sleeveN.

The gate valve shown in dotted lines in Fig. 1 is a hollow blockgenerally cylindrical in form provided with a lateral extension orprotuberance V, which is turned or ground to a true cylindrical surfacesized to fit accurately the cylindrical seat C. The radial dimension ofthe valve V is greatest on the side where the said portion V is located.the opposite and remaining portion at V being materially smaller inradius that is to say, contained well within a circle produced by theradius of the part V. Thus the gate valve as a whole fits loosely in themain chamber C of the valve casing. The lower end of the gate valve issquared off so as to rest and slide on the bottom seat 0. The valve isprovided with opposite slots V which are inclined. A valve carrierconsisting of the nut portion A and lateral extensions A, the nutportion being centrallv threaded to receive the threaded portion c ofthe valve stem is made of such dimensions that it can he slip edsidewise through either of the slots V into the interior of the valve V;

The valve V may be economically manufactured bv being die-cast sincethis mode of roduct'ionwill render it unnecessary to mill or slot theslots V The valve casting may then be chucked by means of an aperture wand the surface V may then be turned or ground or both. Accurate facingof the bottom of the valve V will not be necessarv. die-casting beingsufiiciently accurate in its results.

In the specific construction herein shown the valve is assembled byfirst inserting the carrier A into the interior of the valve V threadingthe portion S of the stem S into the nut part of the. carrier A, the capI-I, sleeve N and gland nut G having previously been assembled, thenslipping the projecting arms A into the guides formed by the ribs R, R,sliding the valve and its carrier into the chamber C and then screwingon the cap H.

WVhen the valve stem S is turned so as to raise the valve carrier theinclination of the slots V causes the cylindrical surface V of thevalve-to be released from the valve seat C and when the arms A guidedbetween the ribs R, R, reach the ends of the slots V the entire valvewill be lifted into the housing provided by the chamber C leaving asubstantially clear passage for fluids from the inlet I to the outlet 0.The reverse movement of the valve stem first lowers the valve into placeand then by-the wedging action of the slots V? slides the valvelaterally on the bottom seat C until the cylindrical valve surface Vseats itself upon the cylindrical seat surface C. It is considereddesirable to shape the valve casing'so that a clearance chamber C willbe. provided beneath the valve V.

.Generically speaking the lowering and lateral wedging of a valve to itsseat is an operation embodied in sundry old and well known structuresbut so far as I am 1nformed these structures all involve a double valveof which the members seat in opposite directions and necessitate moreparts and more diflicult machine work than has been found commerciallypracticable. By dispensing with one of the valve membersI have obviatedthe necessity of making two such members with lnterlockingor'telescoping parts and by employing a cylindrical surface and seat .onthe single wedging member and the casing respectively .I provideengaging surfaces of such ample extent (and yet in reasonably smallcompass) that only moderate lateral pressure is required to secure thenecessary tightness of the valve. By so modifying and adapting thestructure of the valve member the single wedged member suflices, and theemployment of a single wedged member of cylindrical seating surfacereduces the machine operations to a practical minimum, no more in factthan have to be performed in the manufacture of the common globe valve.I claim V I 1. In a valve, a casing provided with a cylindricalvalve-seat, a cylindrical gate valve loosely fitting in the casing, thebody of said cylindrical gate valve being hollow, and the sides providedwith opposite inclined slots, a valve carrier within the hollow valvehaving arms projecting through said slots into guides on the interior ofthe valve casin said guides, and externally manipulabIe means to raiseand lower the carrier for the purposes herein stated.

2. In a valve, a casing having a main chamber cylindrical in generalcontour, a valve seat, a portion of the interior surface of said chamberhaving a smaller radius than the remaining portions, parallel ridges oneither side of said chamber the tops of the ridges being substantiallyin the same cylindrical surface as the said valve seat portion, a smoothflat seat at the bottom of the main chamber having a circumferencesubstantially coincident with the valve-seat cylindrical surface, acylindrical gate valve, having a face to fit the said valve and portionof the casing surface, the said valve having its maximum radius at saidface, the body of the valve being hollow and its sides provided withinclined slots, a valve carrier within the hollow valve having armsprojecting through said slots into guides on the interior of the valvecasing, said guides, and externally manipulable means to raise and lowerthe carrier for the purposes herein stated.

3. In a valve, a casing having a cylindrical valve seat at one side,ahollow cylindrical gate valve loosely fitting in the casing and havinga projecting sector on which is the seating surface, to fit said valveseat, the rear of the valve being smaller in radius to aiford clearance,and the sides thereof provided with opposite inclined slots, a valvecarrier within the hollow valve having arms projecting -through saidslots'into guides on the interior of vthe valve casing, said guides andexternally manipulable means to raise and lower the carrier for thepurposes herein stated.

4. In a valve, a casing having a cylindrical hollow seat at one side, ahollow cylindricalgate valve loosely fitting in the casing and having aprojecting sector on which is the seating surface, to fit said valveseat, the rear of the valve being smaller in radius to afford clearance,and the sides thereof provided with opposite inclined slots, a valvecarrier consisting of a nut having two projecting arms, said nut withinthe valve, and the arms projecting through said slots into guides on theinterior of the casing, said guides, and a threaded valve stem engagingsaid nut, to raise and lower the carrier for the purposes herein stated.

Signed by me at Boston, Massachusetts, this 15th day of September 1911.

ALEXANDER WATSON.

IVit-nesses CHARLES D. WOODBERRY, ODEN ROBERTS.

i Copies of this patentmay be obtained for .f ve cents each, byaddressing the Commissioner of Patents,

' Washington, D. G.

